46 lines
1020 B
C
46 lines
1020 B
C
// SPDX-License-Identifier: GPL-2.0
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// Copyright (c) 2018 Facebook
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#include <linux/bpf.h>
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#include <linux/pkt_cls.h>
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#include <string.h>
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#include <bpf/bpf_helpers.h>
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#define NUM_CGROUP_LEVELS 4
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struct {
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__uint(type, BPF_MAP_TYPE_ARRAY);
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__type(key, __u32);
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__type(value, __u64);
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__uint(max_entries, NUM_CGROUP_LEVELS);
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} cgroup_ids SEC(".maps");
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static __always_inline void log_nth_level(struct __sk_buff *skb, __u32 level)
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{
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__u64 id;
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/* [1] &level passed to external function that may change it, it's
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* incompatible with loop unroll.
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*/
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id = bpf_skb_ancestor_cgroup_id(skb, level);
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bpf_map_update_elem(&cgroup_ids, &level, &id, 0);
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}
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SEC("cgroup_id_logger")
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int log_cgroup_id(struct __sk_buff *skb)
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{
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/* Loop unroll can't be used here due to [1]. Unrolling manually.
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* Number of calls should be in sync with NUM_CGROUP_LEVELS.
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*/
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log_nth_level(skb, 0);
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log_nth_level(skb, 1);
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log_nth_level(skb, 2);
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log_nth_level(skb, 3);
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return TC_ACT_OK;
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}
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char _license[] SEC("license") = "GPL";
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